This might be what some small companies do but most large companies (who have much bigger PC fleets) will have their own SOE so they're not going to stick with the OS the hardware vendor puts on it anyway.

I would recommend Big Brother (http://bb4.com) because:
- The free version works great
- It can be Linux/Unix based (would recommend) or run from Windows
- It gives a simple view of all network connected devices either on 1 or several pages, depending how you configure it
- Can utilise paging / alert acknowleging etc.
- There are many external scripts available at http://www.deadcat.net/ for specialised checking
- It is easy enough to write your own external scripts if you know the basics of shell scripting
- It integrates with LARRD - an RRD based graphical tool that gives you good looking graphs